Disseminated peritoneal leiomyomatosis: a devastating sequelae of unconfined laparoscopic morcellation

INTRODUCTION

The advent of minimally invasive surgery (MIS) has brought about improvements in postoperative outcomes in terms of pain control, recovery and scar cosmesis in the surgical management of symptomatic uterine leiomyomas.(1) A major limitation to minimising the size of incisions used in MIS resides in the need for specimen extraction after surgical excision, especially if the specimen is sizeable. This often necessitates an extension of one of the port sites for retrieval. Electric power morcellation was introduced to mitigate this limitation by enabling intracorporeal morcellation of uterine leiomyomas prior to specimen extraction, and was widely adopted as an adjunct to laparoscopic myomectomies and laparoscopic supracervical hysterectomies.(2-4)

Unconfined laparoscopic morcellation is, however, not without its attendant risks and clinical sequelae, including morcellation-related iatrogenic injuries, endometriosis, parasitic leiomyomas, disseminated peritoneal leiomyomatosis (DPL) or even the inadvertent dissemination of undiagnosed leiomyosarcomas.(5-7) These growing concerns led to the United States Food and Drug Administration (FDA) issuing a black box warning highlighting the risk of cancer spread with the use of laparoscopic power morcellators.(8) We present the case of a patient who was treated at our institution for DPL resulting from previous unconfined laparoscopic morcellation and a brief review of the existing literature to caution against the use of unnecessary unconfined laparoscopic morcellation of uterine leiomyomas.

CASE PRESENTATION

A 37-year-old woman with no other significant past medical history had undergone a previous laparoscopic myomectomy with unconfined power morcellation three years ago at an external institution. She presented to our clinic with a one-year history of intermittent lower abdominal pain with recent worsening. Examination revealed a non-tender abdominopelvic mass. Initial investigations, including a urine pregnancy test, were unremarkable. Initial ultrasonography of the pelvis revealed multiple uterine fibroids and a right lower quadrant subcutaneous nodule of similar echogenicity as the uterine fibroids. Computed tomography (CT) of the abdomen and pelvis was subsequently performed for better characterisation of these lesions. The CT coronal image revealed multiple heterogeneously enhancing masses of similar appearance and attenuation in the right subphrenic extrahepatic region, subcutaneous plane of the right lower anterior abdominal wall, lower abdomen and pelvis (Fig. 1). The maximum diameter of the lesions ranged from 3.9 cm to 17.5 cm, and prominent vessels were seen surrounding the left pelvic mass.

Fig. 1

CT image shows multiple masses in the right subphrenic, lower abdominal and pelvic regions of a patient who presented with disseminated peritoneal leiomyomatosis.

The diagnosis of DPL was established through a high index of clinical suspicion based on the patient’s history of previous laparoscopic power morcellation for uterine fibroids, suggestive CT findings and a subsequent excisional biopsy of the abdominal wall lesion, which revealed a benign leiomyoma.

CLINICAL COURSE

Following extensive multidisciplinary discussions and patient counselling, preoperative angiography and embolisation was planned, followed by definitive surgical excision of the DPL. During preoperative angiography, embolisation of the main feeding vessels to the right subphrenic lesion (branches of the right hepatic, right inferior phrenic and right posterior intercostal arteries) and pelvic lesions (branches of the inferior mesenteric and bilateral internal iliac arteries) was carried out. The patient subsequently underwent laparotomy for excision of her multiple peritoneal leiomyomas. Several concomitant procedures were required, including a total hysterectomy, bilateral salpingectomy, left oophorectomy, high anterior resection, resection of a cuff of diaphragm and dissection of the right subphrenic lesion off the liver.

Final histological examination confirmed the diagnosis of benign leiomyomas in all resected specimens (Fig. 2), and the patient was started on leuprorelin depot injections following discharge as ‘adjuvant’ treatment to minimise recurrence of DPL. Two years post surgery, her follow-up CT demonstrated intra-abdominal and pelvic recurrences. As she was asymptomatic, the patient opted for observation instead of re-resection.

Fig. 2

(a) Haematoxylin and eosin-stained section of the left pelvic leiomyoma shows fascicles of eosinophilic spindle cells (× 100). Immunohistochemical stains show positivity to (b) desmin (× 100) and (c) caldesmon (× 100), and (d) negativity to CD117 (× 100).

DISCUSSION

Parasitic leiomyomas and the more extensive sequelae of DPL have long been reported in the literature to occur either de novo or following conventional myomectomy or hysterectomy procedures.(9,10) However, the number of cases of parasitic leiomyomas and DPL reported has increased significantly following the introduction of laparoscopic power morcellation.(9,10) We have encountered two cases in our practice thus far, one of which is illustrated in this case presentation.

The incidence of parasitic leiomyomas and the more extensive sequelae of DPL following laparoscopic morcellation is estimated at up to 0.95% and 0.35%, respectively.(9,10) Although DPL is relatively uncommon, it has devastating clinical implications, as it tends to occur in women who are relatively young (mean age 40.8 years at diagnosis) and requires extensive excisions, frequently involving multivisceral resections with significant complications and morbidity.(11)

DPL takes an average of 39–132 months to present after initial laparoscopic morcellation, with a mean number of 2.9 lesions (range 1–16) at presentation.(11,12) Unconfined morcellation has been strongly suggested to be a risk factor for the subsequent development of parasitic leiomyomas and DPL.(11) During unconfined morcellation, small leiomyoma fragments and microscopic deposits, which harbour the potential for regrowth into parasitic leiomyomas, are easily dispersed and lost within the peritoneal cavity.(11) The exact pathophysiology behind DPL is postulated to involve a complex interplay among individual patient genetic predispositions, subperitoneal mesenchymal stem cell metaplasia and hormonal influences, abetted by iatrogenic seeding of the abdominal cavity with leiomyoma fragments from unconfined morcellation. Even with extensive peritoneal lavage, it is becoming increasingly clear that surgical removal of tissue fragments arising from unconfined morcellation is often incomplete and that they do not invariably disintegrate in vivo.(9)